When you have symptThese compact clump structures form a large complex shape that keeps out any foreign matter. oms like high fever, fatigue, diarrhea, constipation, abdominal pain, rashes known as pink spots, dry cough, and headache, there is a likelihood of typhoid. So, doctors recommend the Widal test to diagnose typhoid. The bacterium Salmonella enterica serotype Typhi causes typhus.
Infection is caused by eating food and g water contaminated with feces. The Widel test helps detect bacteria that cause typhoid fever by agglutination in the patient’s blood.
People often wish to know the full form of Widal. The fact is that Georges Ferdinand Widal developed the test, so the test is named the Widal Test in his honor. A Widal test is used to assess the presence of serum H and O agglutinins in the patient’s serum.
How is the Widal test for typhoid fever done?
No special preparation is required, and no fasting is required. Blood is taken carefully by inserting a fine needle in the arm vein. The sample is sent to a laboratory for analysis. Results are achieved using slide agglutination and tube agglutination tests.
Agglutination, also known as blood typing, is a process that occurs when an antigen interacts with the corresponding antibody, causing bacteria or red blood cells to agglomerate in the presence of the antibody. These compact clump structures form a large complex shape that keeps out any foreign matter.
Widal Testing Methods:
- Qualitative method
A drop of undiluted blood serum is applied on the slides, followed by a drop of the O, H, AH, and BH antigens. After mixing the contents with a separate applicator, the slide is gently agitated for a minute. The test is considered negative when no agglutination is observed.
- Quantitative method
Performed after a positive qualitative test is a semi-procedural Widal tube test that tests positive antigens with the blood sample to confirm agglutination on slides.
Because the Widal slide test has higher sensitivity but lower specificity, it should be used for detection, but positive slide test results should be confirmed with the Widal tube test.
What is the scope of Widal test results?
Interpreting Widal test reports requires careful study. A Widal blood test is a qualitative and quantitative diagnostic analysis. It is also known as a typhoid test report. For the diagnosis of a Widal blood test, titers of 1:20, 1:40, 1:60, 1:80, 1:160, and 1:200 must be included in the diagnosis to get the test report for typhoid.
What is the Widal test Normal Range Chart?
When the test report in the Widal test normal range chart is negative, it is negative for typhoid fever. When the titer value in the test report is less than or equal to 1:20, 1:40, 1:80, and less than 1:160, then the typhoid test result is in the Widal test value.
What are the positive values of the Widal Tests?
Positive Widal test values indicate a bacterial infection with Salmonella enterica serovar Typhi bacterial infection. S Typhi O positive means active infection with typhus fever. Active infection indicates that the patient has Salmonella enterica serovar Typhi infection. S Typhi H positive means there is a previous infection or shows the result of the serum test report of an immunized person.
What is a negative Widal test?
A negative Widal test means a person does not have an enteric fever, and another infection is causing the symptoms. The titer value of the O and H antigens in the sample is below 1:160.
How much does the Widal test cost?
The Widal test price is affordable. The cost of the Widal test varies from the testing center and other criteria that affect it. The cost of the Widal test ranges from INR 300-500.
- The Widal test is a quick way to diagnose typhoid or enteric fever.
- It only requires the patient’s serum and some reagents to detect the fever.
- However, as various factors can affect test results, it is always best to perform this test a week after infection by following the appropriate instructions.
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